Natural resource management models simplify reality for the purpose of planning or management. In much the same way, an uncertainty model simplifies the many uncertainties that pervade the natural resource management model. However, though a number of uncertainty models have been developed, there has been little work on verifying such models against the uncertainty they purport to represent. The central research question addressed by this work is 'can a natural resource management uncertainty model be verified in order to evaluate its utility in real-world management?' Methods to verity uncertainty models are developed in two areas: uncertainty data models, and uncertainty propagation through process models. General methods are developed, and then applied to a specific case study: slope stability uncertainty in the southern Queen Charlotte Islands. Verification of two typical uncertainty data models (of classified soils and continuous slope) demonstrates that (in this case) both expert opinion inputs and published error statistics underestimate the level of uncertainty that exists in reality. Methods are developed to recalibrate the data models, and the recalibrated data are used as input to an uncertainty propagation model. Exploratory analysis methods are then used to verify the output of this model, comparing it with a high-resolution mass wastage database—itself developed using a new set of tools incorporating uncertainty visualisation. Exploratory data analysis and statistical analysis of the verification shows that, given the nature of slope stability modelling, it is not possible to directly verify variability in the model outputs due to the existing distribution of slope variability (based on the nature of slope modelling). However, the verification work indicates that the information retained in uncertaintybased process models allows increased predictive accuracy—in this case of slope failure. It is noted that these verified models and their data increase real-world management and planning options at all levels of resource management. Operational utility is demonstrated throughout this work. Increased strategic planning utility is discussed, and a call is made for integrative studies of uncertainty model verification at this level. / Arts, Faculty of / Geography, Department of / Graduate

This dissertation describes two theories of risky choice based on a normatively axiomatized partial order. The first theory is an atemporal alternative to von Neumann and Morgenstern's Expected Utility Theory that accommodates the status quo bias, violations of Independence and preference reversals. The second theory is an extension of the Inter-temporal von Neumann-Morgenstern theory of Kreps and Porteus (1978) that features a normatively deduced preference for flexibility. A substantial part of the thesis is devoted to examining equilibrium implications of the inter-temporal theory. In particular, a multi-agent multi-period Bayesian rational expectations equilibrium is shown to exist under certain conditions. Implications to asset pricing are then investigated with an explicit parameterization of the model. / Business, Sauder School of / Finance, Division of / Graduate

In this dissertation, we adopt the viability approach to mathematical finance developed in the book of Karatzas and Kardaras (2020), and extend it to settings where portfolio choice is constrained. We introduce in Chapter 2 the notions of supermartingale numeraire, supermartingale deflator, and viability. After that, we characterize all supermartingale deflators under conic constraints on portfolio choice. Most importantly, we prove a fundamental theorem for equity market structure and arbitrage theory under such conic constraints, to the effect that the existence of the supermartingale numeraire is equivalent to market viability. Further, and always under the assumption of viability, we establish some additional optimality properties of the supermartingale numeraire. In the end of Chapter 2, we pose and solve a problem of robust maximization of asymptotic growth, under some realistic assumptions. In Chapter 3, we state and prove the Optional Decomposition Theorem under conic constraints. Using this version of the Optional Decomposition Theorem, we deal with the problem, of superhedging contingent claims. In Chapter 4, we consider yet another portfolio optimization problem. Under simultaneous conic constraints on portfolio choice, and drawdown constraints on their generated wealth, we try to maximize the long-term growth rate from investment. Application of the Azema-Yor transform allows us to show that the optimal portfolio for this optimization problem is a simple path transformation of a supermartingale numeraire portfolio. Some asymptotic properties of this portfolio are also discussed in Chapter 4.

Thesis: Sc. D., Massachusetts Institute of Technology, Department of Civil Engineering, 1975 / Vita. / Bibliography: leaves 266-271. / Sc. D. / Sc. D. Massachusetts Institute of Technology, Department of Civil Engineering

Historically, hydrologic models have been available only on mainframe computers and have therefore not been used by local water managers to support daily decisions. The development of the microcomputer presents an opportunity for that to change. Mathematical models of soil moisture and river routing are selected, developed and tested for use on a microcomputer as an aid to local water management. The models are then integrated with an appropriate data base in a computer program written for a microcomputer. The result is a Decision Support System for local water managers. In order to evaluate the feasibility of using the Decision Support System, an application of the program to a small hypothetical river and irrigation system is carried out. The speed of execution indicates that the use of the Decision Support System on this class of computer under the present configuration may be possible if software or hardware changes can reduce data transfer times to and from disk.

A dissertation submitted to the Faculty of Engineering and the Built Environment, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree of Master of Science in Engineering. University of the Witwatersrand, Johannesburg, 2016 / Given a flight schedule with fixed departure times and cost, solving the fleet assignment problem assists airlines to find the minimum cost or maximum revenue assignment of aircraft types to flights. The result is that each flight is covered exactly once by an aircraft and the assignment can be flown using the available number of aircraft of each fleet type. This research proposes a novel, non-linear integer programming fleet assignment model which differs from the linear time-space multi-commodity network fleet assignment model which is commonly used in industry. The performance of the proposed model with respect to the amount of time it takes to create a flight schedule is measured. Similarly, the performance of the time-space multicommodity fleet assignment model is also measured. The objective function from both mathematical models is then compared and results reported. Due to the non-linearity of the proposed model, a genetic algorithm (GA) is used to find a solution. The time taken by the GA is slow. The objective function value, however, is the same as that obtained using the time-space multi-commodity network flow model. The proposed mathematical model has advantages in that the solution is easier to interpret. It also simultaneously solves fleet assignment as well as individual aircraft routing. The result may therefore aid in integrating more airline planning decisions such as maintenance routing. / MT2017

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Research in optimizing forest management has focused on single-stand problems to derive optimal harvest sequences in terms of residual basal area or residual stand structure for uneven-aged stands, and timing of pre-defined thinning treatments and clearcut harvests for even-aged stands. Recent research results provide various means of numerically deriving optimal management prescriptions for single-stand problems, thus considering all feasible solutions as opposed to considering only pre-defined harvest alternatives. However, forest-level problems involving aggregates of stands with similar management constraints are usually solved by evaluating pre-defined harvest sequences. Forest-level management optimization problems in which individual stands may be assigned to either even-aged or uneven-aged silvicultural systems have not been modelled. A dynamic forest management model is describer: that prescribes silvicultural treatments for stands within a multi-stand management unit. Results of an application of this approach to an Appalachian hardwood forest, comparisons of individual stand and whole forest optimal solutions, and efficiency of the solution algorithm are discussed. / Ph. D.

As competition has intensified, many American manufacturers have sought alternatives to rejuvenate their production systems. Cellular manufacturing systems have received considerable interest from both academics and practitioners. This research examines three major issues in cellular manufacturing that have not been adequately addressed: applicability, structural design, and operational design. Applicability, in this study, is concerned with discerning the circumstances in which cellular manufacturing is the system of choice. The methodology employed is simulation and two experimental studies are conducted. The objective of Experiment I, a 2 x 3 x 3 factorial design, is to investigate the role of setup time and move time on system performance and to gain insight into why and how one layout could outperform another. The results of Experiment I suggest that move time is a significant factor for job shops and that workload variation needs to be reduced if the performance of cellular manufacturing is to be improved. Experiment II evaluates the impact of setup time reduction and operational standardization on the performance of cellular manufacturing. The results of Experiment II suggest that cellular manufacturing is preferred if the following conditions exist: (1) well balanced workload, (2) standardized products, (3) standardized operations, and (4) setup times independent from processing times. / Ph. D.